Multiple-expansion engine.



PATBNTED JAN'. 27, 190s. r. M. PREsooTT. MULTIPLE EXPANSION ENGIN APPLIUATION FILED PEB. 14, 1898.

H0 MODEL.

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FREDERICK M. PRESCOTT, OF MILWAUKEE, WISCONSIN.

ll/lULTiPLE-EXPANSBON ENGINE.

SFECFIGATIUN forming' part of Letters Patent No. 719,136, dated January 27, 1903.

Application iiled February 14, 1898. Serial No. 670,225.

To cir/ZZ whom, t may concern.'

Be it known that l, FREDERICK M. Pans- COTT, a citizen of the United States, residing at Milwaukeedn the county of Milwaukee and State of 1Wisconsin, have invented certain new and useful improvements in Multiple-Expansion Engines, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

My invention relates to multiple-expansion engines, either single or duplex,having three or more cylinders arranged in line with each other, either horizontally or vertically.

The main object of the invention is to facilitate access to and removal of the pistons and piston-rods Without removing or unbolting either cylinder.

lt consists in certain novel features in the construction and arrangement of the component parts of an engine of this class, as hereinafter particularly described, and pointed out in the claims.

In the accompanying drawings like letters designate the same parts in both figures.

Figure 1 is an axial section of a multipleexpansiontandem engine embodying my improvements, and Eig. 2 is a like view of a slightly-modilied construction.

For the purpose oi' illustration I have shown my improvements in a single exigirle having three cylinders arranged in the same axial line and specially designed for direct connection with a pn mp or compressor, which is not shown.

A, B, and C designate,respectively,thehigh, intermediate, and 10W pressure cylinders, and ct, b, and c their pistons, all arranged in the same axial line with each other. The highpressn re cylinder A is placed next tothe crosshead D, or on the inside, and the low-pressure cylinder C Vtarthest from the cross-head, or on the outside. The inner or high-pressure piston c is connected directly With the cross-head D by a rod d, which passes through a stuffing-box in the inner head c of thecylinder A, and with the 'intermediate piston b by an extension d of said rod d or by a separate rod passing through a sleeve or bushing e in the intervening cylinder-heads. The rod or extension d', connecting the inner and intermediate pistons, is preferably formed in- `head a of cylinder A (No model.)

tegrally with the rod d, but is made larger, so as to form at its junction therewith a shoulder, against which the piston d is secured by a nut f, accessible through the inner end ot` the cylinder A by the removal of its head a'. The piston b is secured on the outer reduced end of the rod or extension d' by a nut f', which is accessible through the outer end ot' cylinder B.

A space is provided between the heads of the intermediate and low-pressure cylinders B and C, and the outer head b of the intermediate cylinder B is made removable, as shown in Figs. l and 2, to afford access to and permit the Withdrawal of the piston b.

The low-pressure or outer piston c is connected by independent rods h h, passing through stuffing-boxes in the inner head of cylinder C and outside of the cylinders A and B, with the cross-head D. Said piston c may be secured on the outer ends of said rods by nuts 'i e', which are accessible through the outer end of cylinder C by the removal of its head. c. The rods d and h 7L may be secured at their inner ends to the cross-head D by keys or by the usual or any suitable fastenings.

From the foregoing description it is obvious that access to the high-pressure piston c may be had by simplydetaching the inner and slipping it upon the rod d toward the cross-head D. This piston .may be removed from said cylinder by simply unscrewing the nut f and slipping it and the piston on the rod d toward the crosshead. lt may be removed from the pistonrod by disconnecting the latter from the crosshead D and thrusting it,\vith the piston b, outward or forcing the cross-head D, With the piston c, inward and then slipping the head ct', nut f, and piston (L over the inner end of said rod d.

Access may be had to the intermediate piston b by simply removing the head b' of cylinder B, and said piston may be removed from said cylinder Without disturbing other parts of the engine by unscrewing the nutf, which secures it on the rod or extension d.

Access may be had to the outer or 10W-pressure piston c by removing the outer head c' of cylinder C, and said piston may be Withdrawn from said cylinder by unscrewing the IOO spirit and intended scope of myinvention.

nuts z' c' without disturbing other parts of the engine.

To provide for the removal of the pistonrod d d', particularly when made in one piece, the inner head of the low-pressure cylinder C may be formed with a central opening and furnished with a cap or detachable covery` of sufficient size to admit of the withdrawal of said piston-rod without its pistons d and b through the cylinder C when said cap or cover, piston c, and the outer head c of said cylinder are removed. For the purpose of removing said piston-rod d CZ without detaching and separately removing the intermediate piston b the inner head of the outer cylinder C may be provided with anv opening and detachable coverj, as shown in Fig. 2, of sufficient size to admit of the withd rawal through said cylinder of the piston h.

Various changes in the minor details of construction and arrangement of the character above mentioned may be made within the I claimk l. The combination in a triple-expansion engine, of the high-pressure cylinder and the intermediate cylinder arranged end to end, the removablehead of the high-pressure cylinder being secured to the forward end of its cylinder, the removable head of the intermediate cylinder being secured tothe rear ofits cylinder, a low-pressure cylinder situated some distance from the rear of the intermediate cylinder and having a removable head at the rear, a single piston-rod, high and intermediate pistons secured directly to said rod, a low-pressure pistou, two rods secured to said piston, and a cross-head to which the said rods of the low-pressure cylinder and the rod of the high-pressure cylinder are attached, substantially as described.

2. The combination in a triple-expansion engine of cylinders arranged in tandem, with a space between the intermediate cylinder ,l

and the low-pressure cylinder; the forward cylinder being the high-pressure cylinder and the rear cylinder being the low-pressure cylinder, a removable head for the intermediate cylinder, the space between the intermediate cylinder and the low-pressure cylinder being sufficient to allow for the removal of said head, a removable head at the forward end of the high-pressure cylinder, a removable head at the rear of the low-pressure cylinder, a single piston-rod common to both the high and the intermediate cylinders, pistons on said rod, a piston for the low-pressure cylinder, two rods secured to said low-pressure piston, and a cross-head to which the two low-pressure piston-rods and the rod for the high-pressure and intermediate pistons are attached, substantially as described.

3. The combination in a triple-expansion engine, of the high, intermediate and low pressure cylinders, a piston for each cylinder, the said high-pressure and intermediate cyl` inders being arranged end to end, a space be-4 tween the rear of the intermediate c linder and the low-pressu re cylinder, an open rame between theintermediateand thelow-pressure cylinders through which the head of the intermediate cylinder can be removed, a central piston-rod extending through the highpressure cylinder and into the intermediate cylinder, the piston of the high-pressure cylinder and the piston of the intermediate cylinder being attached to said rod, a cross-head, side rods exterior to the high-pressure cylinder and intermediate cylinder and extending into the low-pressure cylinder, the piston of the low-pressure cylinder being attached to said rods, substantially as described.

In witness whereof I hereto afX my signature in presence of two witnesses.

FREDERICK M. PRESCOTT. Witnesses:

CHAs. L. Goss, C. J. MORRISON. 

